Centrifugal fan.



o. G. CAMPBELL 1 M. 1551113110011.

CBNTRIFUGAL FAN.

APPLIATION FILED FEB. 20, 1912.

1,053, 1 54. Patented Feb', 18, 1913.

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CHARLES G. CAMPBELL AND MONROE BENBROOK, MILWAUKEE, WISCONSIN, ASSIGNORSTO CREAMERY PACKAGE MANUFACTURING COMPANY, OF CHICAGO, ILLINOIS, ACORPORATION OF ILLINOIS.

CENTRIFUGAL FAN.

Specicationof Letters Patent.

Patented Feb. 18, 1913.

To all whom t may concern:

Be it known that we, CHARLES G. CAMP- BELL and MONROE BENBRooK, bothvcitizens of the United States, and residents of Milwaukee, in thecounty of Milwaukee and State of Wisconsin, have' invented certain newand useful Improvements in Centrifugal Fans; and we do hereby declarethat the following is a full, clear, and exact description thereof.

Our invention refers to centrifugal fans wherein air is introducedaxially and discharged peripherally of the fan-casing through the actionof any type of fan therein, the object of the invention being to producea centrifugal fan which will operate with the least expenditure of powerin ratio to the resistance to be overcome, said fan being particularlyadapted for use in the production of a vacuum.

Heretofore as far as we are laware the inrush of air at the fan axisl ismet with an abrupt face that offers great frictional resistanceincidental to change of the direction of the air from the axial point tothe shedding point of the blades, the said frictional resistance causingback pressure resulting in material loss of power and efficiency, thisbeing especially so in connection with vacuum producing fans.

Our invention contemplates overcoming the above objectionable featuresof fans of this character by the employment of a conicall deector whichis disposed axially of the fan opposite the air intake of the casing. Bythe interposition of this cone it is apparent that the change of thedirectionv of air on entering the fan-casing is eifected with the leastresistance, the same being spreader deflected radially'into a thin sheetthat is evenly distributed to the blades,

- Thus accumulation of aircurrent at the axis of the fan is eliminatedwhereby greater efciency and reduction in power expended is the result.

Another object of the invention is to pro- Vide means for adjusting thearea of. the

air intake opening of the fan whereby the volume of air is correctlyproportioned relative'to the speed and capacity of the fan.

Our present` invention is designed to be used particularly inconnect-ion with vacuum creating apparatus such as disclosed in ourapplication for patent, Serial Number 682362, liled March 8, 1912. i

With the above objects in view the invention consists in certainpeculiarities of construction and combination of parts as hereinaftermore fully set forth with reference to the accompanying drawings andsubsequently claimed.

In the drawings Figure 1 represents a longitudinal sectional view of afan embodying the features of our invention, the section beingindicatedby line 1-1 of Fig.

2; Fig. 2, a face View of the same with parts' broken away Aand parts insection to more clearly illustrate the details of construction; Fig. 3illustrates another form of cone from that shown in Figs. l and 2,.wherein the face of the cone is serrated; Fig. 4, a diagrammatic Viewupon a small scale of an.

other form of our invention applied to a centrifugal fan, and Fig. 5, asimilar view of still another form of our invention.

Referring by characters to the drawings, v

l represents a fan-casing of the snail-shell type having the usualeccentric circular air intake 2, and a peripheral air discharge opening3, the same being tangentially disposed with relation to thecircumference of the casing. A driving shaft 4 is axially alined withthe intake opening 2 and is jour-Y naled in a bearing bracket 5 of anydesired type. As shown 1n Figs. 1 and 2, this shaft projects into thecasing, and has secured thereto a conical deector 6, the point of whichis disposed opposite the casing intake opening.- The conical deiector inthis instance constitutes a hub to which is attached a backing-plate 7that carries the usual series of vanes or blades 8. The front edges ofthe blades are suitably Aconnected to a" disk 9,

which disk in conjunction with the backingplate forms a housing forsaid'blades, it being understood that the disk is centrally apertured toform a receiving opening delecto'r, lwhereby the air passage 1s re-:whereby communication is established vbel stricted or increased as thecase may require,

- said tubular throat being held in its adjusted position by a lock-nut11, which impinges against the outer face of the air intake 2 of thecasing.

From the foregoing description it is apparent that when air is admittedthrough the throat or air intake opening that it will strike the pointof the cone and thus be dis-V dered free-to receive a greater volume ofair,

and hence when said fan is utilized as either a vacuum producer orblower, the vacuum efficiency is increased while the force expended isproportionately reduced.

In some instances, as shown in Fig. 3, we may provide the face of theconical deflector with serrations 12, whereby greater surface area ispresented and the air is more readily broken up into spray formwhereby'a series j of thin even sheets of air are distributed to the fanblade as it strikes said face, itbeing understood however, that while wehave shown the serrations disposed radially that they may be in spiralor any other suitable form desired to produce the result.

" Fig. 4 illustrates a form of the invention wherein the conicalvdeflector 6 is connected to the fan-casing and is therefore non-rotary,the fan A in this instance being revolved about thev conical delector.

Fig. 5 illustrates another form o f the invention wherein thebacking-plate 7 of the fan B is formed in one piece-with the conical,-

deiector 6 it being understood that the fan-casing 1n either the formshown in Fig.

4 or 5 isV p ractically of the same type as that illustrated in Figs. 1and 2.

In connection with describing our invention we have illustrated andspecifically mentioned a conical deflector provided with a concavedcircular surfaceagainst which the intake air contacts. It should beunderstood however, in some instances, we may, without departing'fromthe spirit of our in vention, use a polygonal. form for the deflectorsurface.-

We claim:

1. In a centrifugal fan having a casing provided with an air intake andperipheral discharge, and a fan mounted within the casing in axialalinement with vthe air intake; the combination of a conical deflectorarranged opposite the'air intake, and means for adjusting the air intakeopening relative to said conical deiector.

2. A centrifugal fan comprising a casing provided with an air intake andperipheral discharge, a fan mounted within thecasing, and a sleeve inconnection with the air intake adjustable toward and from the back ofthe fan to increase or restrict the aforesaid intake opening.

3. Inacentrifugal fan; the combination of a casing provided with an airintake openingand peripheral discharge, a fan mountedA within the casingin axial alinement with the air intake, and aA conical deflector carriedby said fan, a. sleeve mounted within the casing air intake opening, andmeans for adjusting said sleeverelative to the face of the conicaldeiector for increasing or restricting the aforesaid intake opening.

4. In a `centrifugal fan having a casing provided with an air intake andperipheral discharge, a fan mounted'within the casing in axiala'linement with the air intake, and a conical deiiector carried by saidfan; the

combination of a sleeve in threaded union C. G. CAMPBELL. MONROEBENBROOK.

the foregoing Witnesses: GEO. W. YOUNG, M. E. DowNEY.

with the fan casing'- intake opening, theA .mouth of the sleeve being inaxial allnem'ent

